Cross hair reticule



July 31, 1951 4 R. E. BROWN 2,562,695

CROSSHAIR RETICULE Filed July 15, 1950 m h v 5 9 3. f7 4/ S on] 1. 3/

RALPH E. BROWN,

INVE N TOR.

A TTORNEV.

Patented July 31, 1951 UNITED STATES PATENT QOFFICE CROSS HAIR RETICULE Ralph E. Brown, Los Angeles, Calif assig'nor, by mesne assignments, to Genisco, Incorporated, Los Angeles, Oalifi, a corporation of California Application July 13, 1950-, Serial No. 173,610

4 Claims. it

My invention relates to reticules for optical or like instruments and more particularly to one having a novel arrangement of means for moving the crosshairs thereof,

The reticule of the present invention can be used in any instrument in which an adjustable reticule is desirable, and it is to be understood that it is not limited to the application herein shown.

Although reticules with adjustable crosshairs are one of the oldest instruments knownto man, the means heretofore proposed to hold and move the crosshairs in the desired spatial relationship have presented many difiiculties. In most instances, the means for mounting the crosshairs have comprised movable elements across which the crosshairs were mounted, which elements were mounted for reciprocal movement on threaded stems or guides and inaccuracies have been produced by looseness of the elements on their guides or stems or by backlash between interengaging threaded parts or intermeshing gears. Furthermore, the known arrangement for mounting and moving crosshairs if accurate movement is to be had, are also expensive to produce and troublesome to maintain in perfect working order.

It is an object of my invention to provide means for very accurately displacing crosshairs in the desired spatial relationship in which the means effecting the movement of the crosshairs are subject to negigible loading so that wear due to friction is practically eliminated.

Another object of my invention is to provide mechanism for moving crosshairs which, al though very simple'provides a high degree of accuracy throughout a long service life.

Still another object of my invention is to utilize crosshairs formed from a strand of a material having sufficient resiliency to hold thev teeth of the gears operating the mechanism under a constant, though light, load thus avoiding any backlash since the surfaces are always in engagement.

A further object of my invention is to so are range the crosshairs that even though the crosshairs provide the force to obviate backlash, there is little, if any, wear of the crosshairs.

Other objects and advantages of the present invention will be hereinafter apparent from the following description, particularly when taken in connection with the accompanying drawing, in which ,ZEigure 1 is an elevational view of a portion of a reticule fitted with adjustable crosshairs cop- 2 1 trolled by the mechanism of this invention; and. Figure 2 is a section taken on line 2?2 of Figure 1, v Referring now to'Figure l, the numeral I!) in: dicates the rear of'the' panel of an instrument,

fitted with crosshairs of. the present, invention,-

the point of intersection of which may be. varied by moving the horizontally arranged hair I I ver-v tically and parallel to the bottom edge I Z of a rectangular window 13 in the panel I6 closed, y a t a slu nt r e and s multane usly, or, in sequence, moving the vertically arranged hair Id at right angles to the horizontal hair H. In this application, shadows. of'the crosshairs are, cast onto the translucent screen coin. iclent,v with the image being projected, but it is understood that the reticule also may be installed at the objective plane or at any other convenient plane in the optical system from where it can be projected as a true image instead of a cast Shadow.

Such adjustable crosshair arrangements are utilized in a large number of optical and like instruments, and the general purpose of my invention is to provide an improved combination of crosshair reticu'le and means for moving the crosshair or hairs and the invention will, therefore, be des r bed eneral y Wi hout re e ence to. any particular instrument or use.

The horizontal hair H is wound on a pair of identical vertical shafts l6 and I! mounted in bearings l8, l9 and 2!, 22, respectively, secured to the back of panel 10 at each side of the window l3. The shafts are rotated in the bearings, in. the embodiment illustrated, in the same direc-, tion and at identical speeds by bevel pinions 23,

24 mounted on the ends of shafts l6 and H, re,-

is fixed to one end of the shaft 28 so that the shaft 23 may be rapidly rotated in either direc tion. Bevel pinions 23 and ,24 are of equal di ameter and bevel "gears 2.6 and 2'! are also ,of' equal diameter and engage the respective pinions at corresponding points so that rotation of the shaft 28 causes identical rotation of the? shafts l6 and IT.

A helical V groove 32, preferably of in-j eluded angle, is cut in the surface of each shaft, he grooves havin identical lead and tu n ng n the same direction. One end of the hair I l is;

secured to one end of one shaft, for instance, by the set screw 33 at the lower end of the vertical shaft IS, the hair is then wound around the shaft in the bottom of the groove 32 for a certain distance as, for instance, for half the length of the shaft. The hair is then taken at exact right angles to the shaft l1 and wound around that shaft in the bottom of the groove 34 therein to the upper end of the shaft to which the free end of the hair is secured as, for instance, by set screw 36.

A pair of horizontal shafts 31, 38 are arranged to extend below and above the opening l3 in the panel In at right angles to the vertical shafts. The shafts 31, 38 are mounted in bearings 39, 4i, and 42, 43, respectively, and may be rotated simultaneously in the same direction by a hand wheel 44 secured to the shaft 38 and bevel gears 46, 41 secured to the shafts 38 and 31, and meshing with bevel gears 48, 49 on a lay shaft 5| mounted in bearings 52, 53 mounted on the panel Ill. The shafts 31, 38 are of the same diameter and a helical V groove 54, 56 also of 60 included angle, and of the same lead as the grooves in the shafts l6 and i1, is formed in the shafts 31, 38.

The vertical hair I4 is secured to one end of the shaft 31 as, for instance, by set screw 51, wound around the shaft in the bottom of the groove 54 for a distance, then led at right angles upwardly to the shaft 38 and wound in the bottom of the groove 56 therein to the end of the shaft where it is secured by the set screw 58. The bearings of the shafts are so arranged that hairs II and I 4, as best seen in Figure 2, do not actually contact one another but yet are very close.

It will be evident by the described arrangement that the operator, by turning one hand wheel with one hand and the other handwheel with his other hand, can vary the point of intersection of the hairs, the hairs being wound off one shaft and wound up on the directly opposite shaft and traversing across the window in doing so.

In order to prevent backlash" which is due to slight imperfections of fit between the gear teeth, such as may arise from wear, I prefer to form each of the crosshairs of a filament of synthetic material having considerable strength in tension and of a resilient nature. I have found by experiment and use that a fine filament of the synthetic fiber available commercially and designated nylon serves very well to provide the requisites of strength in tension, resiliency and opacity.

The hair or filament is installed in place under sufficient tension to hold the driving and driven teeth of each of the meshing gears in constant contact and so avoids inaccuracy due to backlash which might otherwise be present.

As before mentioned, the crosshair or reticule of my invention may be used in a wide variety of optical instruments in some of which only a.

single hair might be required but the novel features of my invention are equally valuable whether a single hair or filament is used or a pair of intersecting crosshairs are required.

It will be noted that friction in the operation of my device is negligible since the filament is merely wound on and off the vertical and horizontal shafts, which may be mounted in ball bearings. There is no possibiliy, therefore, of any binding of the frames on their guides as in known constructions or any inaccuracy due to backlash in the operation of the gears. Furthermore, even though each crosshair is under tension and this tension is used to obviate backlash, there is little, if any, wear of the crosshairs as the same are merely deposited and lifted from the grooves as each pair of shafts is rotated.

Although the now preferred embodiments of the present invention have been shown and described herein, it is to be understood that the invention is not to be limited thereto, for it is susceptible to changes in form and detail within the scope of the appended claims.

I claim:

1. A reticule arrangement, comprising: a pair of shafts each having a continuous helical roove in the surface thereof; means rotatably mounting said shafts on a support with their axes in parallel spaced relation at each side of an opening; an elongated nylon filament secured at its one end adjacent an end of one of said shafts, and initially wound around said shaft in the groove therein for a distance, then extended at right angles to said shaft to the other of the shafts and wound around said other shaft in the groove in the surface thereof toward the end of said other shaft; means securing the other end of the filament adjacent that end of the shaft around which it is finally wound which is at the opposite end to that at which it is secured to the shaft on which the filament is initially wound; and means for simultaneously rotating said shafts to unwind the filament from the groove of one shaft and wind it into the groove of the other shaft to effect displacement of said filament truly normal to said shafts.

2. A reticule arrangement, comprising: a pair of shafts each having a continuous helical groove in the surface thereof; means .rotatably mounting said shafts on a support with their axes in paral-.

lel spaced relation at each side of an opening;

an elongated resilient filament under tension secured at its one end adjacent an end of one of said shafts, and initially wound around said shaft in the groove therein for a distance, then extended at right angles to said shaft to the other of said shafts and wound around said other shaft in the groove in the surface thereof toward the end of said other shaft and having the other end of the resilient filament under tension secured toward that end of the shaft around which it is finally wound which is at the opposite end to that at which it is secured to the shaft on which the same is initially wound; gears mounted on corresponding ends of said shafts; an operating shaft; gears mounted on said operatin shaft engaging with the gears mounted on the grooved shafts, the tension of said filament being effective to urge the engaged teeth of the gears on the grooved shafts against the teeth of the gears on the operating shaft to prevent lost motion between the said gears; and means for rotating said operating shaft whereby said grooved shafts are rotatably driven.

3. A recticule arrangement, comprising: a first pair of shafts each having a continuous helical groove in the surface thereof; means rotatably mounting said shafts on a support with their axes in parallel spaced relation at each side of an opening; a first elongated resilient filament; means securing the one end of said filament adjacent an end of one shaft; said filament being initially wound around said shaft in the groovetherein for a distance, then extended at right angles to said shaft to the other shaft and wound around said other shaft in the groove in the surface thereof toward the end of said other shaft. opposite to that end to which it is secured to the end of the shaft around which it is finally wound; a second pair of shafts each having a continuous helical groove in the surface thereof; means rotatably mounting said shafts on a sup-' port with their axes in parallel spaced relation at each side of an opening and extending substantially normal to the axes of said first pair of shafts; a second elongated resilient filament secured at its one end adjacent an end of one of said second pair of shafts, and initially wound around said shaft in the groove therein for a distance, then extended at right angles to said shaft to the other of said second pair of shafts and wound around said other shaft in the groove in the surface thereof toward the opposite end of said other shaft, means securing the free end of said second filament adjacent that end of the shaft around which it is finally wound which is at the opposite end to that at which it is secured to the shaft on which it is initially wound; means for simultaneously rotating the shafts of the first pair to unwind the first filament from I one shaft and wind it upon the other shaft to effect displacement of the filament truly normal to said first pair of shafts; and means for simultaneously rotating the shafts of the second pair to unwind the second filament from one shaft and wind it upon the other shaft to effect displacement of the said second filament truly normal to the second pair of shafts whereby the filaments of each pair of shafts, in all positions of adjustment thereof, cross one another at right angles 4. A recticule arrangement, comprising: a first pair of shafts each having a continuous helical groove in the surface thereof; means rotatably mounting said shafts on a support with their axes in parallel spaced relation at each side of an opening; a first elongated resilient filament under tension secured at its one end adjacent an end of one shaft, and initially wound around said shaft in the groove therein for a distance, then extended at right angles to said shaft to the other of said shafts and wound around said other shaft in the groove in the surface thereof toward the opposite end of said other shaft; means securing the free end of the tensioned resilient filament to said opposite end of the other shaft; a second pair of shafts each having a continuous helical groove in the surface thereof; means rotatably mounting said shafts on a support with their axes in parallel spaced relation at each side of an opening and extending substantially normal to the axes of said first pair of shafts; a second elongated filament secured at its one end adjacent an end of one shaft of said second pair of shafts, and initially wound around said shaft in the groove therein for a distance,

the surface thereof toward the opposite end of said other shaft; means securing the free end of said second filament under tension to said opposite end of the shaft around which it is finally wound; gears mounted on corresponding ends of each pair of shafts; an operating shaft associated with each pair of shafts; gears mounted on said operating shafts engaging with the gears mounted on the pairs of shafts associated therewith, the tension of said filaments being ef fective to urge the engaged gear teeth of the ears on the ooved shafts against the teeth of the gears on the operating shafts to prevent lost motion between said gears; and means for rotating said operating shafts independently of one another.

RALPH E. BROWN.

No references cited. 

